(1) Field of the Invention
The present invention relates to a photosensitive material for the electrophotography. More particularly, the present invention relates to a photosensitive material for the electrophotography, which is excellent in the electrophotographic characteristics, the adhesion to a substrate or the like, the surface hardness and the printing resistance.
(2) Description of the Prior Art
Among photosensitive materials for the electrophotography, function-separation type photosensitive materials, that is, photosensitive materials comprising an electroconductive substrate and a photosensitive layer formed on the substrate, the photosensitive layer comprising a charge transfer medium and a charge-generating pigment dispersed in the charge transfer medium, and photosensitive materials comprising an electroconductive substrate, a photoconductive organic pigment-containing, charge-generating layer formed on the substrate and a charge transfer layer formed on the charge-generating layer, have attracted attention as photosensitive materials for the electrophotography having an excellent sensitivity.
As the charge transfer medium of the function-separation type photosensitive material, there are used hole transfer substances such as poly-N-vinyl carbazole and phenanthrene, electron transfer substances such as 2,4,7-trinitro-9-fluorenone and complexes of an electron acceptor and an electron donor. When charge transfer substances are low-molecular-weight substances, they are used after they have been dispersed in various binder resins.
Among these resins, resins having a charge transfer property, such as poly-N-vinyl carbazole, are brittle and they are defective in that they are readily peeled from substrates or the like and they are insufficient in the abrasion resistance and shock resistance, and most of resins having no charge transfer property, such as ordinary thermoplastic polyesters and polycarbonates, are satisfactory in the toughness but these known resins are poor in the adhesion to an electroconductive substrate, have a low surface hardness and are not satisfactory in the abrasion resistance and printing resistance.